SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4391172abff287765b43fb44ae21dad0db45cabc32736cb50b0044fbd3dfe42e' 
  AND token = 'vDzG4ziHkQI7BtYbIBM0A6ueGOiXdS+bmM0SBmDygdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}